Rotary cylinder



Feb. 10., 1970 w. E. HEESE ROTARY CYLINDER 2 Sheets-Sheet 1 Filed April 29, 1968 Fi.i

FIG. 2

' INVENTOR WILLIAM E. HEESE ATTORNEYS Feb. 10, 1970 w. E. HEESE 3,494,205

ROTARY CYLINDER Filed April 29, 1968 2 2 Sheets -Sheet 2 FIG. 3

FIG. 4

INVENTOR WILLIAM E. HEESE ATTORNEYS United States Patent 3,494,205 ROTARY CYLINDER William E. Heese, Akron, Ohio, assignor to Hydra Power, Inc., Wadsworth, Ohio, a corporation of Ohio Filed Apr. 29, 1968, Ser. No. 725,084 Int. Cl. FOlb 9/00; F16h 1/12 U.S. Cl. 7489.17 Claims ABSTRACT OF THE DISCLOSURE A device for the conversion of a conventional pneumatic or hydraulic cylinder to a rotary actuator or rotary cylinder by the use of an adapter unit that is designed to utilize the existing parts of the cylinder in order to convert the same into a unit that will translate linear movement of the piston rod into rotary movement of a drive shaft. The rotary actuator adapter unit can be either endmounted or mounted intermediate the cylinder ends as will be described and includes substituting a rack for the piston rod and providing a pinion that meshes with the rack and converts linear movement into rotational movement, the assembled unit being fluid tight.

BACKGROUND OF THE INVENTION Field of invention It has long been known that it is desirable to have a unit wherein linear movement of a piston can be translated into rotary movement of a drive shaft that is meshed through gears with the piston. A conventional illustration of such structure appears in Steiner U.S. Patent 2,844,128.

While rotary actuators of this type have enjoyed commercial success, the same have been disadvantageous in that they have required special construction of a housing or body member that will suitably accommodate the rack and pinion arrangement that is required for such type of unit.

Accordingly rotary actuators have first approached the problem of translating linear movement into rotary movement by building a suitable body portion to house the rotary component and then adding cylinder components to suit the installation.

It is believed apparent that such an approach requires a tailor-made unit that is expensive and has a limited application by its very nature.

SUMMARY OF THE INVENTION It has been discovered that the desired effects of rotary actuators can be achieved without the above noted disadvantages by making a standard type adapter housing that is constructed so as to utilize certain of the compo nents of existing pneumatic cylinders.

As a result of this advance it is possible to materially reduce the cost of installing a rotary actuator in any given installation where pneumatic cylinders already exist. At the same time the advantages of rotary actuation are maintained with the result that a new and improved product has been produced as a result of this invention.

Essentially it has been discovered that by removal of the conventional nose guide that is provided in all cylinders and by further removal of the conventional piston rod that is also provided in such cylinders that the cylinder can be then utilized with other components to function as a rotary actuator.

Thus it has been found that the conventional piston rod can be replaced by a rack member that has one end secured to the piston head and has the rack portion thereof receivable within an adapter housing that is secured to the cylinder. A pilot ring is utilized in the nose ring opening of the cylinder so as to properly locate the adapter unit with respect to the cylinder so that while "ice the interior portions of the adapter and cylinder are in fluid communication with each other, they are nonethe less properly aligned so as to permit the actuating characteristics of the piston to be utilized with the adapter to impart rotary motion to a drive shaft as a result of the linear movement achieved by the piston.

It has also been found that by providing sealing members on the adapter unit and at the point of connection between the adapter unit and the cylinder that the unit can be made fluid tight thereby giving improved results.

Production of an improved rotary cylinder having the above characteristics accordingly becomes the principal object of this invention with other objects thereof becoming more apparent upon a reading of the following brief specification considered and interpreted in the light of the accompanying drawings.

Of the drawings:

FIGURE 1 is a perspective view partly broken away in section and illustrating the preferred form of the invention.

FIGURE 2 is a sectional view taken on the lines 2-2 of FIGURE 1.

FIGURE 3 is a sectional view taken on the lines 33 of FIGURE 2.

FIGURE 4 is a sectional view similar to that of FIG- URE 2, but illustrating a modified form of the invention.

FIGURE 5 is a sectional view of a conventional cylinder before modification.

DETAILED DESCRIPTION OF THE INVENTION Referring first then to FIGURE 5, a conventional cylin der 10 is shown having a cylinder barrel portion 20 which, in turn, has front and rear end plates 21 and 22. A piston 13 and piston rod 13a are disposed within cylinder barrel 20 for reciprocal motion therein in conventional fashion. The end plate 21 has a through central bore which communicates with the interior of cylinder barrel 20 and a nose guide 15 is received therein. As can be seen from FIGURE 5, nose guide 15 also has a through bore and piston rod 13a passes through this bore.

Referring next then to FIGURE 1. the improved rotary cylinder, generally designated by the numeral 10, also includes a cylinder portion 11 and a rotary adapter unit 12 with the arrangement being such that the members 11 and 12 are secured together in fluid tight relationship with each other so that linear movement of the piston head 13 Within cylinder 11 will result in rotational movement of the drive shaft 14 as will be described.

In this regard the cylinder 11 includes the usual cylinder barrel 20 which has its opposed axial ends seated within appropriate annular grooves or recesses 21a and 22a that are provided in known fashion in the end plates 21 and 22 thereof respectively. The side walls of plates 21 and 22 further have fluid inlet ports indicated by the numerals 21b and 22b with such inlet ports communicating between an external source of pressurized fluid and the interior of the cylinder barrel 20 in known fashion as is clearly apparent from FIGURE 2 of the drawings. In this regard, the fluid source and connections have not been shown since they are conventional in construction.

The piston head 13 is conventional in the form illustrated in FIGURE 2 with the invention contemplating that the conventional piston rod 13a be replaced by the rack member 30 so as to utilize the normal operating characteristics of the cylinder 11 and piston 13 for the purpose of imparting rotary movement to the drive shaft 14 as will now be described.

At this point also, the conventional nose guide 15 can be removed to permit the adapter unit 12 to be attached to cylinder 11 as will be described more fully below.

The rack 30 which replaces piston rod 13a, is shown provided with a reduced diameter portion 31 that has a threaded end 32 upon which may be received a retaining nut 33 with the retaining nut 33 and the spacer ring 34 serving to fix the rack with respect to the piston head 13. An additional spacer ring or rings 35 and O-rings 36 may be provided with it also being noted that conventional teeth 37, 37 are provided on a flattened portion of the rack 30 as is clearly apparent from FIGURES 1 and 2 of the drawings.

Considering next the adapter unit 12 which pro ects from one end of cylinder 11 and receives the opposed end of rack 30, the same has a housing 12a and it will be noted that the housing includes a first bore 40 in axial alignment with the longitudinal axis of barrel 20 and a second bore 41 that has its axis at right angles to the axis of bore 40 and is also in communication therewith so as to permit meshing of the teeth 37, 37 of rack 30 with the teeth 42, 42 that are provided on hollow pinion 43 that is received within bore 41. Additionally, the mounting face 44 of the housing 12a is undercut as at 45 so as to receive a pilot ring 46 and an O-ring 47 that serves to seal the units 11 and 12 at their points of mounting and replace nose guide 1311.

In this regard, the existing tie rods 48, 48 of the cylinder 11 can be used with the threaded ends 48a, 48a thereof being received in threaded apertures in the base portion 49 of housing 12a so as to permit both cylinder 11 and adapter unit 12 to be drawn together by the application of the usual nuts 50, 50 on the opposed threaded ends 48b, 48b of rods 48, 48 as clearly shown in FIG- URE 2 of the drawings.

An end cap, generally indicated at 51, and including a cylinder 52 and cap 53 is also secured to the left hand end of the unit 12 in FIGURE 2 by use of draw bolts 54, 54 and nuts 55, 55 with the draw bolts being first secured to the projecting end 44a of the base 49 and then being drawn tight by application of nuts 55, 55.

Referring now to FIGURE 3 of the drawings, it will be noted that the pinion 43 has a central bore 55 through which the driven shaft 14 of the device to be actuated by the improved cylinder may be received with the usual key-way 56 (FIGURE 2) being provided to insure rotational drive of shaft 14 by pinion 43. The existence of bore 55 in pinion 43 thus eliminates the need for an external coupling between the actuator and the driven shaft.

Further, the chamber defined by the housing 12a, and particularly the bore 41 thereof, is sealed against the loss of fluid by hearing caps 57 and 58 that are respectively provided on opposed sides of the teeth members 42, 42 of pinion 43 and that further include O-rings or other sealing units 59, 59 as is clearly apparent from FIG- URE 3 of the drawings. In this regard, the bearing caps 57 and 58, as well as the pinion 43 and shaft 14, are held in axially fixed relationship.

In use or operation of the improved rotary actuator, the actuator unit 12 will normally be delivered to the job site together with the appropriate rack 30 and pilot ring 46. To equip the cylinder for use, it is merely necessary that the nose guide 15 thereof be taken off with respect to the end wall 21d of end plate 21 and further that the retaining nut 33 be removed so as to facilitate removal of the conventional piston rod 13a.

At this time the rack 30 together with spacers 34 and 35 and O-ring 36 can be attached to piston head 13 followed by tightening of nut 33 so that the head 13 and rack 30 are assembled as a unit as shown in FIGURE 2. At this time the pilot ring 46 and the O-ring 47 can be placed in the opening 210 whereupon the actuator unit 12 can be positioned in place.

Assembly of the tie rod members 48, 48 results in connection of members 11 and 12 and at this time it is merely necessary to insert the pinion 43 together with the drive shaft 14 with the same being retained in place by the retaining rings 62 and 63 as clearly shown in FIG- URE 3.

With the unit completely sealed as just described and positioned as shown in FIGURE 2, it is believed that as fluid is introduced under pressure through port 22b that this will result in a movement of piston head 13 and rack 30 to the left with the result that clockwise movement of the pinion 43 and drive shaft 14 will result due to engagement between teeth 37, 37 of the rack and 42, 42 of the pinion.

To return the unit to the position of FIGURE 2, it is merely necessary that fluid under pressure be introduced through port 21b and that the pressure in port 22b be reduced whereupon the piston head 13 will be moved to the right to the position of FIGURE 2.

It is also believed apparent from the foregoing that variations in the degree of rotation in drive shaft 14 can be achieved by altering the length of the cylinder barrels 20 and 52. Thus, for example, for increased rotational movement of the drive shaft 14, the cylinder barrels 20 and 52 would be lengthened.

Referring now to the modified form of the invention shown in FIGURE 4 of the drawings, this contemplates a form of the invention wherein the housing is interposed between the conventional end walls 81 and 82 of a standard cylinder.

In this regard, the cylinder barrel is, in effect, split into a first barrel 83 and a second barrel 84 with these barrels being seated within appropriate undercuts 80a and 80b respectively that are provided on opposed ends of the housing 80. Again, the piston head 85 is connected to rack 86 that is received within the bore 87 of the housing 80 so as to mesh with the pinion 88 that is received in bore 89 of the housing. By this arrangement, the existing ports 90 and 91 are capable of being utilized in known fashion and again, a sealed relationship between the interior of the housing 80 and the cylinder members exists by virtue of employment of O-rings 92, 92 as is clearly illustrated in FIGURE 4.

With regard to installation, the modified form of the invention shown in FIGURE 4 is perhaps somewhat simpler in that it requires only removal of the conventional cylinder barrel and replacement of the same by split cylinder barrels 83 and 84 following substitution of the rack 86 for the conventional piston rod.

Also, the unit shown in FIGURE 4 could also embody the inventive concept disclosed herein in conjunction with a double cylinder unit which is not shown but which merely involves a second assembly similar to split barrels 83 and 84, arranged parallel therewith and including a piston and rack meshing with the pinion. In this regard, the secondary assembly would have an opposite direction of movement thereby giving a double action to the unit.

It should be noted that, in the forms of the invention shown herein, the form shown in FIGURES 1 through 3 is intended to be generally applicable to low pressure installations and would normally be used on pneumatic cylinders using up to p.s.i. pressure while the form shown in FIGURE 4 would generally be more applicable to high pressure hydraulic cylinders utilizing pressures up to 1,000 p.s.i. However, it should be understood that the invention is not intended to be limited in any way to use with cylinders having any specific energizing fluid or utilizing any specific pressure.

It should also be noted that while the two forms of the invention shown have application to different types of cylinders, that most of the parts thereof, such as pinion 43 and rack 30 for example, are interchangeable thereby further reducing costs due to standardization of parts.

Additionally, lubrication can be achieved either by introducing a lubricant into the pressure media or by applying a solid, baked on lubricant such as molybdenum disulfide to all moving parts such as gear rack 30, pinion 43 and piston 13.

It has been shown therefore how a new and improved low cost means for converting linear motion to rotary motion has been discovered by providing an adapter unit which can be secured to any existing cylinder thereby avoiding the need to construct a tailor made unit having a limited use. Thus, by using the adapter unit described above, only standard, mass produced cylinders are required and the same can be easily modified when desired.

While a full and complete description of the invention has been set forth in accordance with the dictates of the Patent Statutes, it is to be understood that the invention is not intended to be limited to the specification herein illustrated. Herein accordingly, modifications of the invention may be resorted to without departing from the spirit hereof or the scope of the appended claims.

What is claimed is:

1. In combination with a fluid operated cylinder that includes a cylinder barrel, opposed end plates, a piston head and opposed sources of pressurized fluid supply located on opposed sides of said piston head, the improvement comprising;

(A) an adapter housing having first and second right angle bores therein that are in communication with each other with said first bore having a closed end and an open end;

(B) mounting means adapted to secure said adapter housing in outwardly projecting relationship with one of said end walls of said cylinder with the open end of said first bore of said housing being disposed in fluid communicating relationship therewith and with said first bore being concentrically aligned with the longitudinal axis of said cylinder barrel;

(C) an elongate gear rack (1) reciprocally mounted in said first bore of said adapter housing,

(2) being freely movable with respect to said cylinder barrel and the end walls thereof, and

(3) having one end secured to said piston head and having its opposed end projecting axially thereof;

(D) a hollow pinion (1) rotatively positioned within said second bore of said adapter housing and (2) being secured against axial shifting in said second bore and (3) having its teeth meshed with the teeth of said rack;

(E) sealing means adapted to seal the interior of said cylinder and housing against the loss of fluid pressure; and

(F) said gear rack being reciprocated by movement of said piston on one side of said adapter housing.

2. The device of claim 1 further characterized by the fact that said mounting means include (A) a plurality of tie rod members;

(B) said adapter housing having a plurality of threaded bores in one end thereof;

(C) said cylinder having a plurality of through bores in said end plates in registry with the bores of said adapter housing;

(D) said tie rods being adapted to be received in said bores of said cylinder and said housing whereby the same can be releasably attached to each other.

3. The device of claim 1 further characterized by the presence of (A) a pilot ring received in the end plate of said cylinder between said adapter housing and one end plate of said cylinder.

4. The device of claim 1 further characterized by the fact that said adapter housing includes an auxiliary cylinder on its outboard side opposite the point of attachment with said fluid operated cylinder projecting from and in substantial axial alignment with said first bore of said adapter housing.

5. An adapter unit for use with a fluid operated cylinder of the character described, comprising;

(A) an adapter housing (1) having first and second right angle bores that communicate with each other, and

(2) adapted to be secured to said cylinder with said first bore projecting from said cylinder in axial alignment therewith;

(B) rotary drive means carried by said adapter housing; and

(C) connecting means (1) interconnecting said cylinder and said rotary drive means of said adapter housing and (2) adapted to translate the linear motion of said cylinder into rotary motion of said rotary drive means upon actuation of said cylinder.

References Cited UNITED STATES PATENTS 1,122,111 12/1914 Hanson 92-5 2,013,301 9/1935 Edsell 7489.17 2,090,342 8/1937 Callsen 7489.17 3,012,448 12/1961 Abraham 7489.17 3,338,140 8/1967 Sheesley 7489.17

MARK M. NEWMAN, Primary Examiner WESLEY S. RATLIFF, JR., Assistant Examiner 

